The present invention relates generally to systems for preparing carbonated beverages and more particularly to a fluid flow metering device for controlling the rate of fluid flow in response to demand changes occurring downstream of the metering device.
Modern methods of preparing beer or other carbonated beverages require the use of deaerated or deoxygenated water. The deaerated water is mixed, in accurately controlled proportions, with a beverage concentrate. The mix is then cooled and carbonated prior to final packaging.
Deoxygenation improves beverage stability during its preparation and during the filling process, and during storage prior to consumption. If the beverage is contained within a can, inclusion of air can permit deterioration of the plastic can lining, thereby damaging the can and spoiling the flavor of the beverage.
In many modern beverage preparation systems, deaeration apparatus is provided. These devices commonly reduce air contained within the water to amounts on the order of a few parts per million. Although this level of deoxygenation is effective for soft drink beverages and the like, air-to-water ratios must be reduced to an order of a few parts per billion for the preparation or brewing of beer. One such deaerating apparatus which is capable of deoxygenating water to these very low levels is disclosed and claimed in U.S. Patent Application Ser. No. 050,158, filed June 20, 1979, U.S. Pat. No. 4,265,167, which is a Continuation of U.S. Patent Application Ser. No. 871,539, filed Jan. 23, 1978, now abandoned, and which is assigned to the assignee of the present invention.
Such systems prepare beverages at a very high rate of speed. The rate of water flow to the deaeration apparatus or deaerator must be carefully controlled between very close limits so that the deaerator is never in need of water on the one hand and never overfilled with water on the other. Since many gallons of beverage are processed each hour, should a system component downstream reduce its demand for water even slightly for only a short time, the deaerator could be quickly overfilled or supplied with an excess of water. Conversely, should downstream demand increase even slightly, the deaerator, in a relatively short period of time, would be starved for water. Of course, neither situation is desirable.
It is therefore a general object of the present invention to provide a system for preparing carbonated beverages or the like wherein the water flow rate to the system deaerator is accurately controlled.
It is a further object of the present invention to provide such a system wherein the water flow rate to the deaerator is controlled responsive to the water flow rate demand placed on the deaerator by downstream equipment.
It is another object of the present invention to provide a fluid flow metering device which controls the rate of fluid flow in response to downstream fluid flow rate demands.
It is still another object of the present invention to provide such a fluid flow metering device for use in a system which prepares carbonated beverages wherein the metering device controls the rate of water flow to the system deaerator in direct relation to the flow rate demand of the deaerator.